Since the invention of the reciprocating piston engine, attempts have been made to improve the engine's performance. Recently, with the escalating fuel prices of the past years, even greater attempts have been made to improve the efficiency of these engines. Also, the problems of air pollution have become serious to the extent that new methods of burning fuels in engines are being utilized with an emphasis for more complete combustion of the fuel. Currently, this is being attempted by improving the air-fuel ratio by leaning the mixture. In order to achieve complete combustion, however, and still retain performance, several devices have been developed to swirl the air-fuel mixture either during the compression stage or during the power stroke. Examples of such devices can be found in U.S. Pat. Nos. 4,467,752, 4,357,915, and 4,162,661.